0.3=0.3-a

Solution for 0.3=0.3-a equation:

Simplifying
0.3 = 0.3 + -1a

Add '-0.3' to each side of the equation.
0.3 + -0.3 = 0.3 + -0.3 + -1a

Combine like terms: 0.3 + -0.3 = 0.0
0.0 = 0.3 + -0.3 + -1a

Combine like terms: 0.3 + -0.3 = 0.0
0.0 = 0.0 + -1a
0.0 = -1a

Solving
0.0 = -1a

Solving for variable 'a'.

Move all terms containing a to the left, all other terms to the right.

Add 'a' to each side of the equation.
0.0 + a = -1a + a
Remove the zero:
a = -1a + a

Combine like terms: -1a + a = 0
a = 0

Simplifying
a = 0